Heat flow

Heat flow is the movement of heat from one location to another. The characteristics of heat flow are determined by the laws of thermodynamics.

Heat flow is an important issue in many industrial applications, and in building construction. Various types of heat-flow barriers may be used in construction, according to the type of heat-flow to be regulated.

There are three types of heat flow:

• Conduction: Heat flow through solids, gels, or still liquids
• Convection: Heat flow through moving fluids (gases or liquids)
• Radiation: Movement of heat as electromagnetic radiation (infrared)

Weatherization is the principal means of slowing convective heat flow. Insulation is the principal means of slowing conductive heat flow. Reflective barriers are used to slow radiative heat flow, and are often directly coupled with insulation.